PACKAGING OF FOOD ->the advantages and disadvantages.

By Brayden Ribeiro

WHY IS IT IMPORTANT?

The packaging that carries your food is designed specifically to allow you to receive the best quality and cheapest product. In other words, it helps you achieve value for money. Many things contribute to this when choosing to package your food. In this wiki, we will be looking at 4 various types of packaging: glass, plastic, aluminium and polyethylene terephthalate (PET). These 4 are all extremely common ways of packaging. Also in this wiki, we will be analysing some, but not all, of the functions of food packaging, and why some products are chosen to package over others.
Some of these functions include:
recycling.gif


  • Physical Protection
  • Barrier Protection
  • Containment
  • Security
  • Durability
  • Mould-ability
  • Corrosion Resistance
  • Ability to Retain Freshness



GLASS -> Why and Why Not?

Glass has been an extremely useful packaging tool used for a variety of goods for centuries. Glass was mainly used to hold wines and oil. But today it holds everything from perfumes to soft drinks. No matter what type of glass - from your bottle or computer - it can be recycled over and over and retain its strength. Glass is made mainly using sand and alkali. When these items are exposed to high temperatures, they fuse together. They are then cooled rapidly, to form a solid structure.






Below, A video demonstrating the strength of glass during transportation.
ADVANTAGES ->

- Chemically Inactive (Inert)
- Impermeable
- Does not produce an odour
- Reusable & recyclable
- Generally suitable for microwave use
- Excellent Clarity


DISADVANTAGES ->
- Weakness - effects transportation (arguable)
- Expense
- Allows Ultra Violet rays & light through
- Higher weight then some alternatives

What do all the "advantages" actually mean ?

All those advantages are great - if you can understand them that is. If an object is chemically inert (or inactive) it means it is no readily able to react with other elements. This can benefit packaging greatly as it avoids any elements or chemicals in the glass to react with the food and taint the taste and freshness. If an item is impermeable, it does not allow fluid to pass through it. This is beneficial for obvious reasons, as glass wouldn't be much of a packager if the fluids would pass through it! Glass can be microwave safe, though it is important to note that not all glass is safe. This is because glass fails or breaks when it is exposed to extreme and rapid temperature change because glass is brittle, and vulnerable to thermal shock. The glasses that are microwave safe have near zero coefficient thermal expansion (meaning they don't expand and shrink with variance of temperature). The other advantages seem to be straight forward, now on to the disadvantages.


What do all the "disadvantages" actually mean ?

With the "weakness" situation, everyone knows glass is not as sturdy as some other packaging options, but the youtube video presented above seems to contradict that if sufficient packing is used, even in harsh conditions the glass stays as one solid instead of tiny broken pieces of glass. Another issue was the expense. If you go into a shop, and buy a bottle of coke ( in a plastic bottle ) it will be cheaper then the coke in a glass bottle. This is because glass costs more to produce. This is where glass loses to plastic, even though glass is environmentally friendly. Also, because glass allows lights and ultra violet rays through (although this is useful is the SODIS process) over exposure to the sun and its rays can contribute to bringing the product closer to the expired date, as some items are not expected to be in such temperatures.








PLASTIC -> Why and Why Not?

Plastics tends to be a wide range of organic synthetic solids. Plastics are usually synthetic polymers with a higher molecular mass, but some have been known to be partially natural. Plastic is a very efficient and common way of packaging - money wise. Corporations use plastic packaging when wanting to maximise profits and minimise expenses, even though it is very bad for the ecosystems as it is difficult to recycle.





plastic_bag.jpg
ADVANTAGES ->
- Durability
- Lightweight
- Versatility
- Resist corrosion
DISADVANTAGES ->
- Environmental concerns
- Losses shape
- Production cost
- Chance of improper consistency resulting in lack of heat resistance
- Can be permeable
- Plastic draw dust



What do all the "advantages" actually mean?

Plastic has many advantages. Plastic is considered versatile because there are many polymer structures that are classed as
"plastics"( A polymer is a repeated sequence of many monomers ). Another reason they are considered versatile, it because plastics can be produced in a variety of colours, making them ideal for consumer products. Plastic is lightweight. It is
important that a packaging resources is lightweight as it effects transport and waste. The heavier it is, the more it is to transport (cost wise) and the more of it there is, the more waste there is. Plastics are also resistant to corrosion by acids, and can be used to package bleach because of this.
lklk.jpg
An image demonstrating taking the aesthetics approach to plastic packaging


What do all the "disadvantages" actually mean?

Plastics pose an environmental concern as not all plastics can be recycled, and those that can be recycled but be separated into groups of different polymer structures. The whole process is very time consuming. Large amounts of crude oil are sometimes needed to create plastics. this is because some monomers are created as a byproduct from cracking long carbon chains such as petrol and diesel. The long chains are cracked to produce short changed alkane and short chained alkene, which is used for making some plastics.






ALUMINIUM -> Why and Why Not?

Aluminium has been and still is a very reliable packaging choice, and it is more then likely you will use something contained in aluminium. There are many reasons for this, such as the cheapness and recyclability of aluminium products. Its so recyclable in-fact, that since the 1980s, around 40 percent of that aluminium is still being used today, through recycling. another facts about aluminium include that only 5 percent
recycle_metalani.gif
of energy is used to recycle aluminium, rather then produce it from scratch. Also, since the 1990's, the weight of aluminium has dropped by 30 percent ! This greatly contributes to persuading producers to use aluminium, and consumers to buy it.


ADVANTAGES ->
- Offers a high level of corrosion resistance
- Optimal protection properties
- Keeps contents fresh (protections from external influences).
- The lightest complete barrier packaging material.

DISADVANTAGES ->
- Reacts with acidic food
- Can’t see contents.
- Storage issues.

What do all these "advantages" actually mean?

Aluminium offers a high level of corrosion resistance. This is because aluminium forms a thin layer of oxide to prevent further oxidisation. When rust is prevented from occurring on your packaging, the food can remain fresh and untainted. Aluminium also offers optimal protection properties, by this we mean
aluminium offers an impermeable metal barrier to light, ultra violet rays, water vapour, oils, fats, oxygen and microorganisms. This again,
images.jpeg
retains product freshness and prevents chemical reacting from occurring between products and other elements outside the packaging. Aluminium also takes the place of the lightest complete packaging material. This helps reduce waste, and makes the recycling process much easier.

What do all these "disadvantages" actually mean?

Since aluminium is a metal, you cannot see through it or its contents. this to an extent can limit the producers ability to draw consumer attention. Aluminium also reacts with acidic food. This means that it cant be used to package such things such as vingar, as the metal will react and pass on an aluminium taste to the product in hand. aluminium can also contain high toxins levels that can go into food and cause the food to go off or poisonous.




POLYETHYLENE TEREPHTHALATE -> Why and Why Not?

Polyethylene terephthalate is the chemical name of polyester, although the name polyester is only used in fibre applications. PET is a clear lightweight packaging option. It is especially convenient in the areas of soft drink, juices and water. The basics of PET are ethylene glycol and terephthalic acid, which are combined to form a polymer chain. The resulting strands of PET are quickly cooled, and cut into small pellets. The pellets are then heated to a molten liquid that can be easily moulded into almost any shape.

ADVANTAGES ->
- Easily mouldable
- Stable and lightweight
- Inexpensive &versatile
- Minimal substance transfers
- Recyclability
- In terms of biopolymer productions, PET ranks last on environmental impact.
- PET does not contain bisphenol-A (BPA) or phthalates (plasticizers).

DISADVANTAGES ->
- Becomes brittle and opaque at increasing crystallisation levels
- When extremely crystallised, the bottle turns white
- Absorbs flavour components of beverage
- Shorter shelf life
- Low thermal resistence



What do all these "advantages" actually mean?

The fact that PET is easily mouldable, mean it allowed for individual bottle shapes, which is appealing to some producers and consumers. PET is also recyclable, this means it is broken down into separate monomers ( as it is a polymer ) and then reconstructed again.Like glass, it is a very strong and inert material that does not react with foods, is resistant to attack by micro-organisms, and will not biologically degrade. Bid-phenol -A and phthalates are common chemicals found in household products. Phthalates are used to make plastics last longer and be more flexible while BPA helps to make plastic clear and shatterproof. S
ome studies have shown these chemicals to have an effect on our health. tests have shown BPA & plasticisers (phthalates) affect reproductive systems. They act as hormone disrupting chemicals. This then leads on to problem with pregnancy such us under weight births. Also, BPA has been linked with cancer and other health issues. Since PET does not contain these two worrying chemicals, it is a very valuable product.


What so all these "disadvantages" actually mean?

Polymers can crystallize upon cooling from the melt, mechanical stretching or solvent evaporation. When this happens, the bottle turns white and "crystalised". Also, PET has been known to absorb flavour of the product. This happens the polymer molecules tangle together like a "sponge" and "soak" up the flavour of the product contained in side of it. The fact that PET has low thermal resistance means that it is not versatile in terms of varying temperatures, and will need to stay at a constant ideal temperature to retain product freshness. PET has also been known to be prone to hydrolytic degradation if not completely dry prior to processing.


REFERENCES -->
Why Is It Important?
Glass - Intro
Microwave Safe
Plastic
Plastic advantages/disadvantages
Aluminium
PET